Anyone out there know how frequent in-bore explosions for the PGU-28 A/B there are?
This round replaces the venerable M56 round, and is supposed to offer better ballistics, and a fuse that will detonate at lower velocities (hence higher ranges) than its predecessor.
It sounds like the fuse is just a bit too sensitive.
US Air Force seeks replacement for high-explosive cannon rounds
By Stephen TrimbleHigh-explosive incendiary (HEI) rounds fired by most US Air Force fighters may soon be replaced in the inventory by inert 20mm bullets.
The General Dynamics PGU-28 A/B 20mm semi-armour piercing HEI round entered service during the last decade with the M61 cannon installed on the Boeing F-15, Lockheed Martin F-16 and Lockheed F-22. As of 2001, the USAF and US Navy had stockpiled 8 million PGU-28 rounds, each of which features a pyrotechnic fuze and a pyrophoric explosive.
But the USAF is now seeking a replacement round, launching a market survey on 1 June to identify potential sources for a “non-fuzed, non-explosive round with PGU-28/B [aerodynamic] performance”, an acquisition notice says. The market survey is being conducted by the Joint Munitions and Lethality acquisition centre at Picatinny Arsenal, New Jersey.
The current stockpile of PGU-28/B rounds “limits mission effectiveness,” the notice adds. Concerns about the safety of the HEI round have surfaced involving in-bore explosions. An upgraded version of the PGU-28/B has satisfied the navy’s Boeing F/A-18 community, but not the air force.
Unlike the F-18, the air force’s fighters have cannons mounted directly beside the cockpit, making in-bore explosions an injury risk for the pilot.
Anticipating the requirement long in advance, Alliant Techsystems (ATK) has licensed manufacturing rights in the USA for a round designed by Germany’s Rheinmetall.
The Penetrator with Enhanced Lateral Effect (PELE) round would provide a tungsten casing that would be shattered on impact by a plastic slug. The effect is a blast of shrapnel spreading outward, or laterally, from the impact area.
The 20mm PELE round for the M61 cannon was designed with the air-to-air role of the fighter as the main focus. However, its utility in strafing runs against ground targets – an increasingly important mission for the USAF – has never been tested, says Rodney Ward, a business development director for ATK Ammunition Systems.
In 2004, ATK received a USAF contract to test the air-to-air effectiveness of the PELE round, Ward says. An operational test and evaluation phase is ongoing and should be completed in the fourth quarter of this year.
The market survey is an indication that the air force will seek alternatives to the PELE round to replace the PGU-28/B. Ward says the programme reflects a major change in combat capability for the air force, rather than just a straightforward replacement for a round already in the inventory.
“This is a whole new capability,” he says. “They [will] have a round that is effectively inert that has a lot of blast effect.”
Penetrator with Enhanced Lateral Effect (PELE)
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PELE technology makes it possible to produce fully inert projectiles. The new technology modifies the projectile performance characteristics,significantly enhancing the accuracy of tank and artillery fire, while substantially reducing the risk of collateral damage. Non-explosive PELE ammunition consists of a high-density casing containing a core made of low-density, low-compressibility material. Upon impact with the target, the low-density material inside the shell is compressed to such an extent that the casing bursts, generating numerous fragments that are propelled in the direction of fire. This way, the round’s lethal impact is restricted to a defined space or limited area, reducing the likelihood of collateral damage. PELE and ALP make it possible to manufacture warheads containing little or no explosive. Moreover, existing ammunition can be inexpensively retrofitted with PELE and ALP technology. Both technologies can be integrated in full- and sub-caliber rounds, and fired from current and future weapon systems.